“Start Quote

It could be ... that science is interested in putting the record straight ”

End QuoteIvan Oransky,MedPage Today

It reflects an increasing problem in the scientific community: a dramatic increase in the number of papers retracted - or taken back - by journals.

When a paper is retracted, it means that the research has so many flaws that it has to be withdrawn by the publications in question. Many consider this action as the worst punishment for a scientist.

In recent years the number of retractions has increased dramatically - in 2000 there were 30 but in 2010 this number had risen to 400.

However, the number of studies published increased by only 44% in that period, according to the journal Nature.

This has serious implications for science.

Although these retractions still represent 0.035% of what is published each year - around 1.4 million studies - the way the scientific community works amplifies the impact of any mistakes.

Researchers base their new studies on previously published work, which means that one paper with flaws can influence dozens of others, whose work will then be used by many others before someone spots the mistake.

Research is reviewed by others before publication

To some, the large increase in retractions is not particularly surprising.

"It could be, as we and others have argued, a good thing and a sign that science is interested in putting the record straight," says Ivan Oransky, editorial director of the US-based organisation MedPage Today.

"That being said, it is often very difficult for critics to get editors to take their concerns seriously, and retractions are taking longer and longer. So it's a complex story," he adds.

“Start Quote

Japanese scientist Haruko Obokata became something of a celebrity last January after publishing a study on stem cells.

It was supposed to be a ground-breaking discovery, but turned out to be a case of fraud.

Ms Obakata's work had passed peer review.

But as soon as another research team tried to replicate Obokata's work, it became evident that there had been an "inappropriate handling of the data".

She has recently been found guilty of misconduct.

Replication

"Science relies on others to replicate the work, it doesn't necessarily have to be exactly the same, but in a way that guarantees that other results can be replicable," Nigel Hooper, professor of biochemistry School of Molecular and Cellular Biology, told BBC Mundo.

"We don't go out there and ask someone to repeat the study; the replication is a natural part of the scientific process," he adds.

Damian Pattison, executive director of the PLOS One journal, says: "The thing is that peer reviews aren't exempt from problems.

"It is very difficult to understand what's going on in a paper, unless you see all the data.

"And the problem is that in the majority of cases, the scientists don't include all the data in their report.

"So there may be many reasons why a study may have a good peer review and later it turns out that it is unreliable."

'Selective' presentation

Dr Elizabeth Iorns, a cancer biologist and CEO of Science Exchange (where scientists can share information), says the literature often does not correct itself.

She believes that the peer review system has several issues, with each reviewer expected to assess a publication that contains data generated by a team of researchers with highly specialised backgrounds.

The individual peer reviewer may not have expertise in all of the techniques used, in particular complex statistical analyses.

And she says: "There is evidence that researchers sometimes selectively present data that supports a specific hypothesis.

"This means that reviewers do not have access to all of the data generated from the research study and cannot determine if the information provided accurately represents the complete dataset."

A couple of years ago, Ivan Oransky founded Retraction Watch with science journalist Adam Marcus. The mission of this blog is to highlight cases of retractions, mistakes and corrections.

These journalists have a lot work ahead of them, judging by the study made by Danielle Fanelli, a natural scientist who specialises in the study of scientific misconduct, bias and related issues and a member of the Research Ethics and Bioethics Advisory Committee of the National Research Council in Italy.

Not all data is shown to reviewers

According to a study of his, published in 2009 in PLOS One and based on the metadata of several surveys, about 2% of scientists have admitted to falsifying, making up or modifying elements at least once.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.